The Lancaster as a potential nuclear bomber in 1945

[Peter Gunn]

"Carrying" the nuke and "Delivering" the nuke are two totally different objectives. I'm sure the Lancaster was capable of carrying the nuke, but are you seriously trying to say that a plane that will be flying at maybe 20,000 feet (or less) at less than 200 mph, from a base/support structure that is still well within range of Japanese air power at the time can deliver this bomb?

What about the survival of the crew and a/c? The Enola Gay didn't do that turn and dive away just to look cool.

I'm not trying to be insulting but I think you're not only grasping at straws but the argument of using a Lancaster for this mission is a non starter.

nuuumannns's post #118 is about a concise an argument as you'll get for why the Lancaster was probably never really considered, not to mention it's inability to fulfill the mission profile.

Cheers.

 

[Shortround6]

The Lancaster VI had a ceiling of 28500ft at 65000lb (max TO weight) whilst carrying all three turrets..

B-29 ceilings are all over the place depending on weight (I am willing to bet the Lancasters are too, for both types of engines) but the B-29 carried just over 40,000lbs of fuel in the wing/fuselage tanks (with a tank in each bomb bay over 15,000lbs of fuel was added) so one has to be very careful when considering B-29 performance.
Running "light" (combat weight) at 101,000lbs a B-29 had a "ceiling" (100fpm climb) of 39.600ft using "normal" power (2400rpm vs take-off and max power of 2800rpm)

a regular B-29 had a basic weight (empty equipped) of 74,050lbs. Max take-off was 140,000lbs.

By the time a B-29 was in the target area thousands of pounds of fuel had been burned off. The Lancasters would also burn off fuel and be able to fly higher but the B-29 with it's turbos is going to have an advantage. The engines could make 2000hp at 2400rpm at 35,600ft. That I believe is a max continuous rating, Military rating was 2200hp at 2600rpm and WEP was 2500hp at 2800rpm as of June 1945.

 

[RCAFson]

"Carrying" the nuke and "Delivering" the nuke are two totally different objectives. I'm sure the Lancaster was capable of carrying the nuke, but are you seriously trying to say that a plane that will be flying at maybe 20,000 feet (or less) at less than 200 mph, from a base/support structure that is still well withing range of Japanese air power at the time can deliver this bomb?

What about the survival of the crew and a/c? The Enola Gay didn't do that turn and dive away just to look cool.

I'm not trying to be insulting but I think you're not only grasping at straws but the argument of using a Lancaster for this mission is a non starter.

nuuumannns's post #118 is about a concise an argument as you'll get for why the Lancaster was probably never really considered, not to mention it's inability to fulfill the mission profile.

Cheers.

Did you not read the previous posts? The Hiroshima mission dropped the bomb at 30k ft, while the Lancaster VI had a service ceiling of 28500ft at Max TO weight while carrying full armour and armament. The Silverplate B-29s had all armament and armour except the tail guns removed. A standard B-29 had a service ceiling of 23800ft at Max TO weight but this rose to 35800ft combat altitude at combat weight (weight over the target). A standard B-29 carrying a 10k lb bomb from Tinian has to TO at near max TO weight to carry enough fuel. Take a Lancaster VI and remove the forward two turrets and their crew and ammo and all armour and the TO service ceiling will be well above 30K ft.

The Lancaster VI's Merlin 85 engines are not even a high altitude rated Merlin even though they have two stage SCs.

We've already established that Tinian was well inside IJ aerial strike range. When flying Atomic strike missions from Tinian aircraft had the option to land on Okinawa or Iwo Jima after weapon release. I haven't done the numbers but this profile might have allowed an overloaded Lancaster VI to have flown from Tinian without resort to in-flight refuelling.

 

[Jugman]

Tinian was easily within reach of IJ twin and single engined Kamikaze attacks:

Japanese air attacks on the Mariana Islands - Wikipedia

In any event, using in air refuelling, the Lancaster could deliver the bomb from Tinian.

That's because at the time Japan still had possession of Iwo Jima. Once Iwo Jima was in Allied hands the Japanese attacks on the Mariana Islands pretty much stopped. Both Okinawa and Iwo Jima were far more vulnerable to Japanese attack.

 

[Kevin J]

Did you not read the previous posts? The Hiroshima mission dropped the bomb at 30k ft, while the Lancaster VI had a service ceiling of 28500ft at Max TO weight while carrying full armour and armament. The Silverplate B-29s had all armament and armour except the tail guns removed. A standard B-29 had a service ceiling of 23800ft at Max TO weight but this rose to 35800ft combat altitude at combat weight (weight over the target). A standard B-29 carrying a 10k lb bomb from Tinian has to TO at near max TO weight to carry enough fuel. Take a Lancaster VI and remove the forward two turrets and their crew and ammo and all armour and the TO service ceiling will be well above 30K ft.

The Lancaster VI's Merlin 85 engines are not even a high altitude rated Merlin even though they have two stage SCs.

We've already established that Tinian was well inside IJ aerial strike range. When flying Atomic strike missions from Tinian aircraft had the option to land on Okinawa or Iwo Jima after weapon release. I haven't done the numbers but this profile might have allowed an overloaded Lancaster VI to have flown from Tinian without resort to in-flight refuelling.

You need about 2400 miles for a Tinian-Tokyo, Tokyo-Iwo Jima sortie. IIRC you have about 2200 miles without the saddle tank. Removing the dorsal turret without adding some extra fuel would probably do the trick. IIRC the Tallboy raid against the Tirpitz was about 2400 miles. Then of course you have higher altitude Merlin's available. Okinawa-Tokyo-Okinawa is about 1930 miles, no problem. Also, it was estimated during WW2 that removing all the Lancaster's turrets would have added 50 mph to its speed, so does that correspond to about 20% better range? In which case, 2400 miles is well within a Lincoln's reach unarmed and top speed would go up to 367 mph.

 

[nuuumannn]

Take a Lancaster VI and remove the forward two turrets and their crew and ammo and all armour and the TO service ceiling will be well above 30K ft.

Got figures to back that up? On the first page I provided charts and historical information based on trials carried out with B.I Special Lancs, which definitely prove that the Lancaster's performance at MTOW carrying a sizeable load was too slow, at too low an altitude and did not have the range to mount such an operation.

Let's see what the Lanc VI could do. The Impact of the local conditions would have sapped the performance of the Lanc VI as it did the B.I Special in trials, which would, at MTOW reduced its speed, altitude and range with a given load. Yes, it was more powerful, as was the Lincoln, but not that much more powerful, certainly not B-29 powerful. That the B-29 managed the performance that it did flying those ops from Tinian is remarkable for the time, particularly the fact that standard B-29s were doing it on a daily basis. No other bomber in service could have done it, frankly.

Also, we are again ignoring the fact that historically, neither the Lanc VI nor the Lincoln were available by August 1945 to be of any use in service bar for training and familiarisation (three, yes, three Lincolns entered service in August 1945 with 57 Sqn), let alone mount a long range special operation of the nature of nuclear attack.

 

[GrauGeist]

Tinian was easily within reach of IJ twin and single engined Kamikaze attacks:

Japanese air attacks on the Mariana Islands - Wikipedia

In any event, using in air refuelling, the Lancaster could deliver the bomb from Tinian.

Just to recap on this, Tinian (and neighboring islands) were under attack until February 1945, when the air attacks ceased.

The reason they ceased, is because the base that the Japanese were using as a staging base, was on Iwo Jima - which came under Allied assault in February.

From that point on, the only way the Japanese would able to reach Tinian, is with a G4M clean, as the distance from the Home island or Formosa to Tinian was within it's max. ferry range, but not with a substantial loadout.

 

[RCAFson]

Just to recap on this, Tinian (and neighboring islands) were under attack until February 1945, when the air attacks ceased.

The reason they ceased, is because the base that the Japanese were using as a staging base, was on Iwo Jima - which came under Allied assault in February.

From that point on, the only way the Japanese would able to reach Tinian, is with a G4M clean, as the distance from the Home island or Formosa to Tinian was within it's max. ferry range, but not with a substantial loadout.

That's not true. The IJ attacks ceased before the US captured Iwo Jima, and they ceased because IJ had run out of resources and US bombing of IJ airfields. In fact there was a variety of other bases from which raids could be staged but Japan was too weak to continue their offensive:

Even during the months when Iwo absorbed most of its attention, the Seventh went on with its routine neutralization of other enemy bases which could have threatened the Marianas. That mission was to continue until the summer of 1945, and it is useful here to interrupt the Iwo Jima story with a brief summary of operations elsewhere.

Marcus, through which planes could stage from Japan to Saipan--though with longer flights than via Iwo--was kept under constant surveillance, usually by armed reconnaissance missions of two or three B-24's. Between September 1944 and July 1945 such missions totaled 565 sorties. Using Marcus as a target for shakedown missions, XXI Bomber Command dispatched eighty-five B-29's against it during the last month of the war.35 Woleai was visited occasionally by AAFPOA planes, as was Yap, until responsibility for the latter island was turned over to a Marine air group at Ulithi in November.36 Truk, in spite of its severe mauling earlier, was considered a potential danger spot which needed more than sporadic armed reconnaissance, and missions were sent against its installations until the end of the war. Until 26 June 1945 it was AAFPOA's B-24's that did most of the work there, flying 1,094 sorties after 1 August 1944, of which 595 came after the t groups had moved from Kwajalein to the Marianas. The half-dozen or so fighters that the Japanese managed to keep patched up did not offer much resistance, but AAFPOA was generous with escorts, sending P-38's in 75 sorties, P-47's in 234 escort and strafing sorties.37

Until the assault on Iwo Jima the B-24's continued the antishipping campaign in the Bonins. After 6 November there were no more bombing attacks, but with technical aid from NAVY officers the 42d Squadron carried out a number of mining missions against harbors and anchorages in the islands. By 12 February the 42d had planted 275 mines, about half of them around Chichi Jima.38 In his official report Harmon said that the squadron had not been successful in its

objective of clearing the area of all ships over 2,000 tons, and the Joint Army-Navy Assessment Committee credited the B-24's with sinking only a single ship with its mines. Nevertheless, there was some belief in the Marianas that Harmon had deliberately minimized the effectiveness of the campaign "because mine-laying was not considered a proper function for B-24 bombers."39

Capture and Development of Iwo Jima
Japanese raids against B-29 bases, though troublesome, were not important enough alone to have justified the cost of capturing Iwo Jima: the decision to seize the island was made a month before the raids began and they had ceased seven weeks before Iwo was assaulted. Meanwhile, the island had proved a hindrance to the VHB campaign in other ways. Since fighters based on the rock had attacked B-29's en route to or from Japan, to avoid interception the bombers had been forced to fly a dog-leg course which complicated navigation and reduced bomb loads; even then, enemy radar at Iwo gave early warning to Honshu of northbound Superforts. But the idea of seizing the island derived less from its menace while in Japanese hands than from its potential value as an advanced base for the Twentieth Air Force.
HyperWar: The Army Air Forces in WWII: Vol. V--The Pacific: MATTERHORN to Nagasaki [Chapter 19]

 

[RCAFson]

Got figures to back that up? On the first page I provided charts and historical information based on trials carried out with B.I Special Lancs, which definitely prove that the Lancaster's performance at MTOW carrying a sizeable load was too slow, at too low an altitude and did not have the range to mount such an operation.

Let's see what the Lanc VI could do. The Impact of the local conditions would have sapped the performance of the Lanc VI as it did the B.I Special in trials, which would, at MTOW reduced its speed, altitude and range with a given load. Yes, it was more powerful, as was the Lincoln, but not that much more powerful, certainly not B-29 powerful. That the B-29 managed the performance that it did flying those ops from Tinian is remarkable for the time, particularly the fact that standard B-29s were doing it on a daily basis. No other bomber in service could have done it, frankly.

Also, we are again ignoring the fact that historically, neither the Lanc VI nor the Lincoln were available by August 1945 to be of any use in service bar for training and familiarisation (three, yes, three Lincolns entered service in August 1945 with 57 Sqn), let alone mount a long range special operation of the nature of nuclear attack.

The Lancaster VI didn't have the range of a B-29 but it certainly had a greater bomb load capacity and proved it during actual missions. Lets not forget that the B-29s failed in their attempt at high altitude precision bombing of Japan under General Hansell due to poor bombing accuracy and unacceptable engine failure rates and instead used stripped aircraft to conduct a low level night bombing campaign under Lemay. The Silverplate B-29s were specially modded and stripped aircraft and by war's end only about 30 had been produced, under the highest production priority, or about the same number as Lancaster VIs and Lincolns with very low production priority. The first Lancaster VI was built in late 1943 under an experimental program but this certainly wasn't due to a lack of production capacity, but rather a lack of suitable targets and production incentive similarly there was little incentive to prioritize production of the Lincoln because there was no need for it in the ETO and Commonwealth participation in the final campaign against Japan had not yet been decided upon.

Lancaster VI performance:
http://www.wwiiaircraftperformance.org/merlin-lovesey.pdf (p.221)

and given that Iwo Jima and Okinawa were in US hands both could have been used to shorten a Lancaster/Lincoln atomic mission range.

It is pretty obvious that Lancaster VI ceiling would increase as weight decreases (just as in every other aircraft).

 

[mcoffee]

Lets not forget that the B-29s failed in their attempt at high altitude precision bombing of Japan under General Hansell due to poor bombing accuracy and unacceptable engine failure rates and instead used stripped aircraft to conduct a low level night bombing campaign under Lemay

The B-29s discovered the jet stream. Did the Lancaster have a bomb sight that could compensate for 200+mph winds aloft? What would the ground speed of a Lancaster be with a 200 mph headwind?

We've already established that Tinian was well inside IJ aerial strike range.
That's not true. The IJ attacks ceased before the US captured Iwo Jima, and they ceased because IJ had run out of resources and US bombing of IJ airfields.

So, which is it?

 

[FLYBOYJ]

The Silverplate B-29s were specially modded and stripped aircraft and by war's end only about 30 had been produced, under the highest production priority.

Not entirely true - what started out as a "modification" actually turned into a production line option. 46 were produced during the war, 65 total.

 

[Peter Gunn]

Did you not read the previous posts?

*SNIP*

Not trying to be insulting but yes, I have read what has been posted, my question is, have you?

As an aside, how is the Lancaster carrying the A bomb? Is it fully internal or is part of it sticking out like the Grand Slams?

I ask because back on page 4 of this thread, railroader and special ed brought up the issue of arming the bomb in flight, problematic in a Lancaster?

 

[GrauGeist]

That's not true. The IJ attacks ceased before the US captured Iwo Jima, and they ceased because IJ had run out of resources and US bombing of IJ airfields. In fact there was a variety of other bases from which raids could be staged but Japan was too weak to continue their offensive:

The last bombing raid against Tinian was on 2 February, 1945 - Iwo Jima came under attack by Allied forces 17 days later.

The Japanese were losing too many aircraft for little gain plus they lost their staging base to conduct such raids, so the units, most of which were launched from the Home island (using Iwo Jima as a stop-over) were used to either attack Allied units who were now engaged at Iwo Jima or they were held in reserve for Home defense.

 

[fliger747]

Something to bear in mind here was that the bomb's (2) were developed simultaneously with the B-29. Weapon and delivery were sensibly devised to work hand in hand. Had there been no B-29 some other configuration of the bombs and or aircraft used would have been developed.

Leave it in Tokyo Bay with a submarine?

 

[Shortround6]

Did you not read the previous posts? The Hiroshima mission dropped the bomb at 30k ft, while the Lancaster VI had a service ceiling of 28500ft at Max TO weight while carrying full armour and armament. The Silverplate B-29s had all armament and armour except the tail guns removed. A standard B-29 had a service ceiling of 23800ft at Max TO weight but this rose to 35800ft combat altitude at combat weight (weight over the target). A standard B-29 carrying a 10k lb bomb from Tinian has to TO at near max TO weight to carry enough fuel. Take a Lancaster VI and remove the forward two turrets and their crew and ammo and all armour and the TO service ceiling will be well above 30K ft.

The Lancaster (with which ever engines) was not going to operate within several thousand feet of it's service ceiling. Few, if any, planes ever did.
Service Ceilings are also usually established or rated at standard conditions (59 degrees F/15 degrees C at sea level and standard pressure) with a corresponding drop in temperature at high altitudes. While the air does get colder at high altitudes even in the tropics you have to be a lot higher than 30,000ft for the temperature to be uniform regardless of surface temperature. one old chart shows minus 48 degrees F at 30,000ft on a standard 59 degree F day but a "hot day" (100 degrees F to 6000ft) shows about -5 degrees F at 30,000ft.

Adjust as you see fit but the Lancaster will NOT have the same ceilings in the summer operating from the Marshals as it did in testing in England (no plane would).

The Turbos on the B-29 allowed the same power ratings as lower altitudes to be maintained well into the 30,000ft altitude range.

BTW while not used in combat in WW II the B-29 was capable of lifting quite a large bomb load (given enough runway)

perhaps the caption is in error and those are only 12,000lb bombs? in which case the B-29 is carrying a mear 24,000lbs.

The Lancaster VI's Merlin 85 engines are not even a high altitude rated Merlin even though they have two stage SCs.

and here we run into a problem, if you fit higher altitude rated Merlins you loose around 30hp per engine at take-off. (on a 59 degree standard day)
TANSTAAFL. as it was the Merlin 85s were allowed to use 18lbs of boost for take-off.
The altitude rated Merlin 86 was rated at 1440hp at 22,000ft at 18lbs boost. the Merlin 85 gave 1580hp at 16,000ft at 18lbs.
Both engines had the same cruise ratings and the same climb rating although the Merlin 86 could maintain int higher. The Merlin 86 was intended for a high altitude Lincoln project.

 

[wuzak]

Something to bear in mind here was that the bomb's (2) were developed simultaneously with the B-29. Weapon and delivery were sensibly devised to work hand in hand. Had there been no B-29 some other configuration of the bombs and or aircraft used would have been developed.

Leave it in Tokyo Bay with a submarine?

If plane and bomb were developed together there would have been no need for special modifications.

Thin Man was supposed to be the first bomb used, and the B-29 needed extensive modifications to carry it.

The fact is that the B-29 was being developed before the A-bomb project started, and by the time the B-29 started flying, maybe even became operational, the scientists had no idea what size and shape the A-bombs would be.

 

[Shortround6]

The amount of secrecy exceeded the absurd. Even several years post war the sketchest details possible were given to the aircraft designers charged with designing and build the planes that would carry the bombs.
Ed Heinemann tells a story in his autobiography about getting a visit from some security people about a drawing of the bomb bay for the A3 Skywarrior. The specs from the government just said how long, how wide and how tall the bomb bay should be. Heinemann drew a bomb shape in the empty space and claims he traced a drawing of a Sante Fe steam locomotive wheel to get the circular shape. It turns out he was within 1 in of the diameter of the proposed bomb the A3 was supposed to carry and the security people wanted to know how he knew the actual dimensions!!!!
Much like GE Lynn Massachusetts was not allowed to talk to GE Schenectady New York about jet engine problems/solutions because one was working on a centrifugal engine and the other was working an axial engine. (obviously sharing information on burner design, fuel feed, turbine wheels/blades and shafting/bearings would compromise national security

 

[RCAFson]

The Lancaster (with which ever engines) was not going to operate within several thousand feet of it's service ceiling. Few, if any, planes ever did.
Service Ceilings are also usually established or rated at standard conditions (59 degrees F/15 degrees C at sea level and standard pressure) with a corresponding drop in temperature at high altitudes. While the air does get colder at high altitudes even in the tropics you have to be a lot higher than 30,000ft for the temperature to be uniform regardless of surface temperature. one old chart shows minus 48 degrees F at 30,000ft on a standard 59 degree F day but a "hot day" (100 degrees F to 6000ft) shows about -5 degrees F at 30,000ft.

Adjust as you see fit but the Lancaster will NOT have the same ceilings in the summer operating from the Marshals as it did in testing in England (no plane would).

The Turbos on the B-29 allowed the same power ratings as lower altitudes to be maintained well into the 30,000ft altitude range.

BTW while not used in combat in WW II the B-29 was capable of lifting quite a large bomb load (given enough runway)
View attachment 529097
perhaps the caption is in error and those are only 12,000lb bombs? in which case the B-29 is carrying a mear 24,000lbs.



and here we run into a problem, if you fit higher altitude rated Merlins you loose around 30hp per engine at take-off. (on a 59 degree standard day)
TANSTAAFL. as it was the Merlin 85s were allowed to use 18lbs of boost for take-off.
The altitude rated Merlin 86 was rated at 1440hp at 22,000ft at 18lbs boost. the Merlin 85 gave 1580hp at 16,000ft at 18lbs.
Both engines had the same cruise ratings and the same climb rating although the Merlin 86 could maintain int higher. The Merlin 86 was intended for a high altitude Lincoln project.

The use of twin external bombs on the B-29 was a post war project and the resulting aircraft had a very short range. During WW2 the Lancaster carried heavier bomb loads against actual targets.
The B-29 required about 1/3 more TO run than a Lancaster and 2% reduced Lancaster TO power, due to higher altitude rated engines, could be compensated for by a longer TO run.

The Lancaster VI with full armour and 3 turrets had a service ceiling of 28500ft at 65000lb and maximum speed was 313mph at ~18300 FT.

The Lancaster VI with 1 turret (rear - this configuration was used by many of these aircraft) had a service ceiling of 21800ft at 72000lb (22000lb bomb load) while maximum speed was 345mph ( The Avro Machester, lancaster and Lincoln). Fuel load was 1672 IG and range 1550 miles. With a 10k lb bomb, potential fuel load was ~3300IG but this figure might not be possible depending on bomb dimensions and the ability to carry auxiliary tanks. However, both the Fatman and Littleboy bombs were considerably shorter than a Tallboy and this would allow for considerably more internal fuel via auxiliary tanks.

So we see that increasing MTOW by 7000lb reduced service ceiling by 6700ft but aircraft flying from Tinian would have burnt off about
14k lb of fuel for a weight of 58k lb at weapon release. This would equate to a service ceiling of ~35k ft.

EDIT: Air temperature at weapon release was -33c (-27f) for the Hiroshima mission. True wind was less than 10mph for both missions (Malik). Given that the Hiroshima yield was much less than Nagasaki, it is evident that the crew were in little danger since the Nagasaki release was at 28.9k ft versus ~31.6k ft (Malik discusses the uncertainty around Enola Gay's actual altitude at weapon release).

"Carrying" the nuke and "Delivering" the nuke are two totally different objectives. I'm sure the Lancaster was capable of carrying the nuke, but are you seriously trying to say that a plane that will be flying at maybe 20,000 feet (or less) at less than 200 mph, from a base/support structure that is still well within range of Japanese air power at the time can deliver this bomb?

What about the survival of the crew and a/c? The Enola Gay didn't do that turn and dive away just to look cool.

I'm not trying to be insulting but I think you're not only grasping at straws but the argument of using a Lancaster for this mission is a non starter.

nuuumannns's post #118 is about a concise an argument as you'll get for why the Lancaster was probably never really considered, not to mention it's inability to fulfill the mission profile.

Cheers.

Why would a Lancaster VI be flying at 20K ft whilst dropping a 10k lb bomb?

 

[nuuumannn]

The Lancaster VI with full armour and 3 turrets had a service ceiling of 28500ft at 65000lb and maximum speed was 313mph at ~18300 FT.

In trials in the UK, not in the Pacific under operational conditions.

Sigh. This defence of the Lancaster VI is starting to sound like the Fw 187 argument. It was not put into production and on the existing timeline, i.e. arguing about the readiness of Okinawa and Iwo Jima and the use of an aeroplane that didn't enter scale production is just wishful telescoping. Nobody's saying these aircraft couldn't carry a (Little Boy) nuclear bomb, but not on the mission profile and environment the B-29s did.

The fact that the Fat Man was the prototype of a production weapon meant that the Lancaster would be useless since in whatever form it couldn't carry the Fat Man. Little Boy was intended for a single bomb only and wasn't intended on production.

 

[FLYBOYJ]

In trials in the UK, not in the Pacific under operational conditions.

YEP!

From Wiki;
"The more powerful engines proved troublesome in service and were disliked by ground maintenance staff for their rough running and propensity to 'surge and hunt', making synchronisation impossible. This was caused by variations in the fuel/air mixture and over time would damage the engine."

Lancaster VI service ceiling of 28,500 (as posed by RCAF son) - both Atomic missions dropped their bombs at 31,000 feet.

So as mentioned earlier - Could the Lancaster deliver a nuclear weapon? I believe so. As good as a B-29? NO. With greater risk? Definitely!

I also have issues with a single pilot cockpit.